Gear shaping is a cutting process wherein a gear of a desired tooth profile with cutting capability can generate the similar tooth profile in a workpiece, i.e. a “blank”, mounted on a work table. Gear shaping can be used to generate a tooth profile on the outer periphery of a workpiece, or the inner periphery of the workpiece. Additionally, gear shaping is particularly advantageous when shaping gears having a shoulder, i.e. a secondary flange, below the inner or outer periphery containing the tooth profile and in close proximity thereto.
As it relates to the general state of the art, reference can be had to U.S. Pat. Nos. 3,628,359; 4,136,302; 4,254,690; 4,533,858; 4,542,638; 4,629,377; 4,784,538; 5,345,390; and 7,097,399, the entire disclosures of which are also hereby incorporated by reference in their entireties. As can be generally appreciated from the above, gear shaping is a cutting process wherein a spindle fixedly carrying the cutting gear linearly and vertically reciprocates across the inner or outer periphery of the workpiece to successively cut the desired tooth profile. The cutting gear and workpiece also rotate relative to one another during cutting in the same manner that the finished gear would mesh with its mating gear during operation.
As will be appreciated from the aforementioned references, there are several problems that arise with conventional gear shaping machines. As one example, the linear and vertical stroking is typically accomplished by a complex linkage also referred to as a stroke drive that extends between a static mounting location on the gear shaping machine and the moving spindle. As such, to change movement of the spindle with respect to stroke length, speed, and/or position, separate additional motors and axes of control are required throughout the stroke drive.
As another example, the vertical working direction of conventional gear shaping machines restricts shaping operations to a single spindle. Such a restriction can be disadvantageous when machining more complex gearing such as splines or the like which can have a plurality of different tooth profiles, each of which dependent upon the position of the other ones of the plurality of tooth profiles. When manufacturing such a construction, a single spindle vertical shaper can only do one profile at a time. To move on to a subsequent profile, tool change or other set-up operations can affect the accuracy of the relationship between the plurality of tooth profiles resulting in poor gear performance.
In view of the above, it is therefore desirable to have a gear shaping machine that overcomes the aforementioned problems with conventional designs.